Title: Bale actuated control for the rear roll forming chamber in a crop material roll forming machine

Description: CROSS REFERENCES TO RELATED APPLICATIONS

Reference is hereby made to the following co-pending U.S. applications dealing with related subject matter and assigned to the assignee of the present invention:

1. "Synchronizing Roll Forming and Wrapping Operations in a Crop Material Roll Forming Machine" by Aquila D. Mast, U.S. Ser. No. 656,661, filed Feb. 9, 1976.

2. "Controlling the Size of a Roll Core Formed in a Crop Material Roll Forming Machine" by Wilson L. Strausser et al, U.S. Ser. No. 656,663, filed Feb. 9, 1976.

3. "Front and Rear Upper Aprons in a Crop Material Roll Forming Machine" by Aquila D. Mast, U.S. Ser. No.. 656,687, filed Feb. 9, 1976.

4. "Material Layer Diverting Means for a Crop Material Roll Forming Machine" by Aquila D. Mast, U.S. Ser. No. 656,752, filed Feb. 9, 1976.

5. "Mechanism for Opening and Closing a Crop Material Roll Forming Region in a Roll Forming Machine" by Robert L. Rice et al, U.S. Ser. No. 656,753, filed Feb. 9, 1976.

6. "Crop Material Roll Forming Method and Machine" by Jack W. Crane et al, U.S. Ser. No. 656,758, filed Feb. 9, 1976.

7. "Raising and Lowering Mechanism for the Rear Chamber in a Crop Material Roll Forming Machine" by Robert L. Rice et al, U.S. Ser. No. 656,759, filed Feb. 9, 1976.

1. FIELD OF THE INVENTION

The present invention relates generally to the art of harvesting loose crop material and, more particularly, is concerned with a method and machine for forming rolls of crop material, such as large round bales of hay or the like.

2. DESCRIPTION OF THE PRIOR ART

Several decades ago, small roll balers for forming small rolls or round bales of crop material were reasonably popular for a short time as one method of harvesting crop material, such as hay or the like. However, small roll balers failed to successfully compete over the long run with the predominate method of harvesting hay, that being, the utilization of automatic type balers that form the hay into small wire- or twine-tied rectangular bales. Consequently, the small roll baler method of harvesting hay has since substantially faded from the hay harvesting scene.

In recent years, the practice of harvesting hay by forming it into large rolls through the use of large roll or round balers has become increasingly popular. One type of large round baler forms a swath or windrow of hay into a large cylindrical roll or round bale while the latter is supported on the ground. Another type of large round baler picks up the swath of windrow of hay and forms it into a large round bale off the the ground. Both of these types of large round balers generally have mechanisms for applying twine or similar binding material about the bale once it has reached its desired maximum size. Then, in the case of both types of balers, the wrapped bale is discharged from the baler.

In the case of the on-the-ground type of large round baler known up to the present, the baler must be guided away from the windrowed crop material during the time the twine wrapping and bale discharging operations are being carried out since this type of baler is not capable of receiving additional hay until these operations are completed.

In the case of the off-the-ground type of large round baler known up to the present, the forward movement of the baler must be temporarily suspended or halted until the twine wrapping and bale discharging operations have been completed since this type of baler is also not capable of receiving additional hay during the performance of these operations.

Under certain field and crop conditions, the amount of time consumed in wrapping and discharging bales may approach twenty-five percent of that spent in actually rolling or forming the hay into individual bales when utilizing either of the on-the-ground or off-the-ground types of large round balers. It is readily apparent that such state of affairs creates a serious limitation on the potential, long term bale production capability of the large round balers. The same was generally true also in the case of the new obsolete small round balers.

One attempt to obviate the above-described limitation was proposed in U.S. Pat. No. 3,004,377 in connection with the small round baler. Such proposal related to the provision of auxiliary conveyor means on the baler to accumulate hay being picked up, by circulating it in an endless path on the baler away from the bale forming mechanism, while the bale wrapping and discharging phases of the baler operations are being carried out at the location of the bale forming mechanism. Then, once the latter operations are completed, it was envisioned that hay accumulated on the baler would be fed into the bale forming mechanism of the baler along with hay being picked up from the field to form another roll or round bale.

However, certain critical drawbacks are presented by the above-described proposal. First, the continuous circulation of the incoming hay by the auxiliary conveyor, while wrapping and discharging of the roll from the bale forming mechanism is being carried out, will likely result in substantial leaf losses in such portions of the hay due to over-handling thereof. Second, it is quite likely that more than enough hay to form a bale will soon become accumulated in the auxiliary conveyor of the baler and therefore periodically the machine will probably have to be operated while its forward movement is stopped in order to clean out the auxiliary conveyor. Consequently, the operator would have to give some attention to the auxiliary conveyor part of the baler in order to know when to do this. Third, the continuous circulation of the hay in loose form by the auxiliary conveyor makes it very difficult to maintain the degree of control over the circulating hay that is necessary in order to subsequently be able to carry out smooth feeding of the accumulated hay into the bale forming mechanism of the baler along with hay being picked up from the field.

SUMMARY OF THE INVENTION

The preferred embodiment of the roll forming machine, as disclosed herein, includes various unique features for facilitating continuous movement of the machine across the field and delivery of crop material to the machine even during the performance of roll wrapping and discharging operations by the machine which overcome or avoid the limitation and drawbacks respectively presented by the prior art round balers and the solution proposed in the aforesaid patent.

While these unique features are particularly adapted for facilitating the continuous, non-stop formation and discharge of round bales by the roll forming machine disclosed herein, it will be readily apparent that some of such features may be incorporated, either singly or together, into conventional round balers and thereby improve the same. Also, some of these features comprise inventions claimed in other copending applications cross referenced above; however, all are illustrated and described herein for facilitating a complete and thorough understanding of those of the features comprising the present invention.

The present invention relates to those features incorporated by the machine for sensing the arrival of a partial roll into a rear one of two separate roll forming chambers on the machine from a front one of the chambers. Due to the provision of two separate roll forming chambers in the machine, incoming crop material is constantly being added to a roll being compactly formed in either of the two chambers. Consequently, there is no over-handling of the crop material, leaf losses due to material handling are minimized and constant control is maintained over the material while it is in the machine. Further, due to the feature for sensing the arrival of the partial roll or core formed in the front chamber into the rear chamber, the performance of the continuous roll forming, transferring and discharging operations may be more dependably and consistently coordinated in the machine.

Accordingly, the present invention relates to the method of forming crop material rolls by a mobile machine adapted to move across a field and having front and rear roll forming chambers, which method broadly comprises the steps of moving the machine across the field, delivering crop material to the machine, initiating formation of a roll of crop material in the front chamber, transferring the roll from the front chamber to the rear chamber after the roll has been partially formed in the front chamber, sensing the arrival of the partially-formed roll into the rear chamber and completing formation of the roll in the rear chamber in response to the sensing of the arrival of the roll therein.

More particularly, an inlet opening to the rear chamber is initially maintained at a first size adapted to allow the transfer therethrough of the roll from the front chamber into the rear chamber. When the roll is transferred, its arrival into the rear chamber is sensed. Then, in response to such sensing, the inlet opening to the rear chamber is reduced to a second size less than the first size and adapted to allow the delivery therethrough of crop material for completing formation of the roll in the rear chamber.

The present invention also relates to a crop material roll forming machine which is broadly comprised by a mobile frame adapted to move across a field, means on the frame for delivering crop material to the machine, a front chamber and a rear chamber on the frame, the front chamber including means for initiating formation of a roll of crop material therein, means associated with the front and rear chambers for transferring the roll from the front chamber to the rear chamber after the roll has been partially formed in the front chamber, means associated with the rear chamber for sensing the arrival of the partially-formed roll into the rear chamber and the rear chamber including means for completing formation of the roll in response to the sensing of the arrival of the roll therein.

More particularly, the machine also includes mechanism on the frame operable for adjusting an inlet opening to the rear chamber between a first size to allow the delivery therethrough of crop material for forming a roll in the rear chamber and a second size larger than the first size and adapted to allow the transfer therethrough of the partially-formed roll from the front chamber. Further, means is provided on the frame for controlling the operation of the inlet opening adjusting mechanism. The controlling means includes a member in the form of a pivotally mounted paddle which is positioned for engagement by the transferred roll to actuate the paddle with the controlling means thereby causing operation of the adjusting mechanism to adjust the inlet opening of the rear chamber from its second to its first size.

Other advantages and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the course of the following detailed description reference will be frequently made to the attached drawings in which:

FIG. 1 is a left side elevational view of a crop material roll forming machine embodying the principles of the present invention;

FIG. 2 is a right side elevational view of the machine of FIG. 1;

FIG. 3 is a plan view of the lower portion of the machine of FIG. 1, on a slightly smaller scale, showing the pickup unit, floor and lower apron, the front chamber floor ramps and the rear chamber bale trip mechanism;

FIG. 4 is a enlarged, fragmentary side elevational view taken along line 4--4 of FIG. 3, showing one of the pivotal floor ramps of the front chamber and rotatable means to raise the ramp;

FIG. 5 is an enlarged, fragmentary side elevational view taken along line 5--5 of FIG. 3, showing the rear chamber bale trip mechanism;

FIG. 6 is an enlarged, fragmentary, top plan view of the forward half of the machine, with the front and rear upper aprons being omitted and the floor, lower apron and pickup unit being omitted except for fragmentary portions thereof;

FIG. 7 is an enlarged, left side elevational view of the rear half of the machine of FIG. 1, showing the various relative positions of the rear chamber opening-and-closing mechanism;

FIG. 8 is an enlarged, fragmentary, front elevational view taken along line 8--8 of FIG. 1, showing twine wrapping mechanism of the machine;

FIG. 9 is a left side elevational view taken along line 9--9 of FIG. 8;

FIG. 10 is a fragmentary, plan view taken along line 10--10 of FIG. 8;

FIG. 10A is an enlarged, fragmentary sectional view taken along 10A--10A in FIG. 10, showing the positional relationship of the twine strands through the notch;

FIG. 11 is an enlarged, fragmentary, left side elevational view of an upper portion of the machine of FIG. 1, showing most of the components of three different groups of control components for synchronizing the continuous roll forming, wrapping and discharging operations performed by the machine;

FIG. 12 is a schematic representation of the hydraulic components for controlling the operation of the front and rear chamber opening-and-closing mechanisms and the twine wrapping mechanism;

FIG. 13 is a front elevational view of the preferred form of crop material layer diverting means associated with the front chamber opening-and-closing mechanism and the rear end of the front upper apron;

FIG. 14 is an enlarged sectional view taken along line 14--14 of FIG. 13; also showing the relationship of the teeth of the diverting means to the transverse bars of the front upper apron as the bars move around hubs on a shaft connected to the front chamber opening-and-closing mechanism;

FIG. 15 is a perspective view of an alternative form of crop material layer diverting means attached to approximately every third one of the transverse bars of the front upper apron;

FIG. 16 is an enlarged sectional view taken along line 16--16 of FIG. 15;

FIGS. 17 through 24 are schematic representations of the machine of FIG. 1, showing successive stages of the operations performed by the machine, as it is moved across a field, in continuously forming, wrapping and discharging large rolls or round bales of crop material; and

FIGS. 17A through 24A are schematic representations of various ones of the control components of the machine of FIG. 1, showing the respective relative positions of the components at the various stages of the operations performed by the machine correspondingly depicted in FIGS. 17 through 24.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following description, right hand and left hand references are determined by standing at the rear of the machine and facing in the direction of forward travel. Also, in the following description, it is to be understood that such terms as "forward," "rearward," "left," "upward," etc., are words of convenience and are not to be construed as limiting terms.

IN GENERAL

Referring now to the drawings, and particularly to FIGS. 1 and 2, there is shown a machine for forming crop material such as hay or the like into rolls, commonly referred to as large compact round bales, the machine being indicated generally by numeral 10 and comprising the preferred embodiment of the present invention (the left side of the machine being shown in FIG. 1 and the right side of FIG. 2 when one is standing to the rear of the machine and facing in the direction of forward travel).

The machine 10 is provided with a mobile frame, generally indicated at 12, which includes left and right longitudinally extending rails 14,16 and transverse pipes (not shown) which interconnect the longitudinal rails 14,16. The longitudinal rails 14,16 are respectively supported by left and right ground wheels 24,26 being rotatably mounted to respective stub shafts (not shown), each of which is secured to and extends outwardly from one of the longitudinal rails 14,16 at an intermediate location therealong.

The frame 12 further includes various upright structures respectively connected at their lower ends to the longitudinal rails 14,16, namely, short rearwardly-inclined left and right rear channels 28,30, left and right middle upright rails 32,34 and left and right front upright beams 36,38.

The upper ends of corresponding left and right short rear channels 28,30 and middle upright rails 32,34 are respectively interconnected by forwardly-inclined left and right side beams 40,42, with left and right rear side sheets 44,46 respectively secured about their peripheries to corresponding left and right longitudinal rails 14,16, short rear channels 28,30, middle upright rails 32,34 and side beams 40,42 so as to close the side openings respectively formed by these latter interconnected structures.

Also, an upper rectangular frame structure (see FIG. 6), including front and middle cross tubes 48,50 and left and right side tubes 52,54, extends between and interconnects with middle upright rails 32,34 and front upright beams 36,38 at the upper ends thereof.

The frame 12 at its forward end includes left and right forwardly-inclined support beams 56,58 which are respectively secured at their rear ends to the lower ends of left and right front upright beams 36,38 and at their front ends to the lower end of a front rack structure 60 which is secured at its upper end to front cross tube 48.

A transverse tubular beam 62 also extends between and interconnects with the front ends of left and right support beams 56,58. At an intermediate location along the transverse beam 62 is secured a forwardly-extending tongue 64 for the machine 10 having a hitch element 66 at its forward end which adapts the mobile frame 12 to be secured to a tractor, or other towing vehicle, located at the front thereof. While the preferred embodiment of the machine 10 described and illustrated herein is a pull-type unit, it should be understood that the mobile frame 12 could readily be modified to form a self-propelled unit.

Also, the machine 10 is provided on its mobile frame 12 with crop material delivery means, generally designated 66, which defines the bottom for two tandemly-arranged roll forming chambers, namely, a first or front roll forming chamber, generally designated by numeral 68, and a second or rear roll forming chamber, generally designated by numeral 70. The crop material delivery means moves crop material from the field into one or both of the roll forming chambers 68,70. Further, a first or front chamber opening-and-closing mechanism, generally designated 72, is provided on the mobile frame 12 in operative association with the first chamber 68, and a second or rear chamber opening-and-closing mechanism, generally designated 74, is provided on the mobile frame 12 in operative association with the second chamber 70. Still further, a twine wrapping mechanism, generally designated 75, is provided on the mobile frame 12 being located generally above the delivery means 66 and between the chambers 68,70.

The components of the delivery means 66, chambers 68,70, the opening-and-closing mechanisms 72,74, and the wrapping mechanism 75 as well as drive means and control components which synchronize the operations performed with the machine 10, will be described in detail hereinafter. Following thereafter, the systematic operations performed by the machine 10 during its continuous, non-stop formation, wrapping and discharge of crop material rolls, commonly referred to as large round bales, will be described in detail.

CROP MATERIAL DELIVERY MEANS

Referring still to FIGS. 1 and 2, but more particularly to FIG. 3, the crop material delivery means 66 includes a crop material pickup unit 76 mounted at the lower front end of the mobile frame 12 and crop material conveying means extending between the ends of the mobile frame 12 comprising a floor 78 fixedly mounted between longitudinal rails 14,16 of mobile frame 12 and extending from adjacent the rear side of the pickup unit 76 to the rear end of the mobile frame 12, and a lower conveyor or apron, generally designated 80, mounted to the mobile frame 12 for movement along an endless path extending along the upper and lower surfaces of the floor 78 and about opposite ends of the floor 78.

The pickup unit 76 is a conventional type, including a horseshoe-shaped drum 82 having a series of transversely spaced, circumferential slots 84 (FIGS. 3 and 6) and a central transverse shaft 86 within the drum being rotatably mounted to vertical side panels 88,90 connected to opposite ends of the drum 82. A series of cam-actuated bars 91 extend transversely between and are rotatably mounted at their opposite ends in circular plates 92 disposed adjacent the ends of shaft 86. The bars 91 mount spaced apart spring tines or fingers 93 which extend outwardly through the series of slots 84 and traverse about a endless clockwise path, as viewed in FIG. 2, the lower portion of which is close to the field, as the shaft 86, bars 91, and plates 92 are rotated which results in fingers 93 continuously picking up a swath or windrow of crop material from the field and feeding it rearwardly over the top surface of the drum 82 and onto the front end of the floor 78 and lower apron 80 as the machine 10 moves across the field. The drive arrangement for the shaft 86 of the pickup unit 76 will be described later on.

The lower apron 80 preferably comprises a series of endless, flexible link-type chains 94 (FIGS. 3 and 6) which are transversely spaced apart even distances and respectively extend around driven sprocket gears 96 which are mounted to a driven shaft 98 which is rotatably supported adjacent the forward end of the floor 78 in bearings mounted respectively in brackets 100 (only right bracket 100 being shown in FIG. 2) fixed respectively to the undersides of support beams 56,58. The drive arrangement for the driven shaft 98 will be described later.

Also, the pickup unit 76 is pivotally supported at the rearward ends of its side panels 88,90 upon the lower apron driven shaft 98 by bearing brackets (not shown) which fit about the shaft 98 and are fastened to the respective side panel rearward ends. The forward end of the pickup unit 76 is yieldably restrained against downward movement by a spring (not shown) secured at its upper end to the right support beam 56 and at its lower end to the right side panel 90. Also, a ground wheel 102 is rotatably mounted to right side panel 90 for supporting the pickup unit 76 on the field.

At the rear end of the floor 78, cylindrical guide members 104 are formed on transverse tube 106 which extends between and is mounted to opposite side sheets 44,46 to provide rear guide means around which chains 94 extend.

The floor 78 is supported by a series of channel beams 108 (FIG. 4) which are connected to and extend transversely between longitudinal rails 14,16. The upper courses of the chains 94 (being seen in FIG. 3) preferably slide within channels 110 which are fixed on the upper surface of the floor 78 while the lower courses of the chains 94 extend along the lower surface of the floor 78.

Each of the chains 94 comprising the lower apron 80 has aggressive type lugs 112 connected thereto at longitudinally-spaced positions therealong which project verticaly-outwardly from the chain 94. The upper courses of the chains 94 move from front to rear in the direction of the arrows shown in FIG. 3 and the lugs aggressively engage the crop material received from the pickup unit 76 for delivering it in a rearward direction and also aggressively engage the roll or rolls of crop material being formed in the rear chamber 70 or in both the front and rear chambers 68,70, as will be described in detail later, in order to facilitate rotary movement of the roll or rolls in a counterclockwise direction, as viewed in FIG. 1. Such engagement of the lugs 112 with the roll also tends to align the stems and fibers of the crop material in substantially circumferential relationship about the roll to provide a substantial tendency for the completed roll to shed moisture when lying in the field.

The rear or discharge end of the floor 78 has terminal supporting means comprising a series of similar plates 114 (FIGS. 3 and 7) mounted at their forward ends to the rearmost one of transverse beams 108 and yieldably urged upwardly to normally assume rearwardly-inclined positions, such as seen in FIG. 7, by left and right springs 116 (only the left spring being shown) being anchored at their upper ends to corresponding left and right side sheets 44,46 by brackets 118 and connected at their lower ends to a transverse rod 119 which supports the undersides of plates 114. The plates 114 are transversely spaced apart from each other so as to receive therebetween the chains 94 and the lugs 112 which project therefrom. Thus, when the rear ends of the plates 114 are in their normal elevated position, the chains 94 and lugs 112 will disappear through the spaces between the plates as they approach the discharge or rear end of the floor 78 which results in the lugs positively disengaging the roll being rotated counterclockwise, while the lower surface of the roll slidably rotates in a rearward direction with respect to the floor 78.

When a roll has been formed to a desired size in the second chamber 70, the discharge of the roll over the rear end of the floor 78 depresses the plates 114 and allows the lugs 112 of the chains 94 to again engage the lower surface of the roll up to the point at which the chains pass around and below the rear transverse tube 106. When discharge has been completed, springs 116 immediately restore the plates to their normal, rearwardly-inclined position with their rear ends in an elevated position with respect to the end of the floor 78.

The pickup unit 76, floor 78 and lower apron 80, to the extent just described heretofore, preferably are substantially the same as shown and described in U.S. Pat. No. 3,859,909, except that the floor 78 and lower apron 80 of the machine 10 have a greater length in the machine 10 in order to accommodate their arrangement as the bottom of the unique front and rear roll forming chambers 68,70 of the machine 10, such not being known heretofore. Other components and mechanisms not known heretofore which are operatively associated with the floor 78 will be described in detail later on.

The front chamber 68 in which, at various periods during the continuous operations performed by the machine 10, a core of a crop material roll is formed will be described next.

FRONT ROLL FORMING CHAMBER

Referring again to FIGS. 1 and 2, the front chamber 68 includes a front upper apron, generally designated 120, and means for movably mounting the upper apron 120 to the mobile frame 12 at a location above generally the forward half of the floor 78 and lower apron 80 which form the bottom of the front chamber 68. The mounting means includes a takeup-and-expansion mechanism, generally designated 122, for movably mounting a front portion of the front upper apron 120 to the mobile frame 12 and additional components for movably mounting rear and lower portions of the front upper apron 120 to the mobile frame 12. The mechanism 122 controls contraction (takeup) and expansion of the front upper apron 120 during roll core formation in the front chamber 68 and also controls the size of the roll core in a manner which will be described later.

The front upper apron 120, per se, preferably has a construction similar to that of the upper apron disclosed in U.S. Pat. No. 3,915,084. The apron 120 is composed of a pair of left and right endless, flexible link-type chains 124,126, illustrated in FIGS. 1 and 2, located adjacent corresponding interior sides of the mobile frame 12, with a series of rigid bars 128 extending transversely between and connected at their opposite ends to the chains 124,126 at longitudinally spaced intervals therealong. The bars 128 thereby extend across substantially the full width of the front chamber 68. In cross section, the bars 128 are preferably cylindrical, but may be square or any other suitable geometric shape, for purposes of offering resistance to bending of the bars, especially when engaging the periphery of a core of a roll of crop material being formed within the front chamber 68, such as illustrated in FIGS. 21 and 22.

At similar locations adjacent to, and spaced downwardly from the upper ends of, the left and right front upright beams 36,38 of mobile frame 12 is mounted the left and right portions of the takeup-and-expansion mechanism 122. The mechanism, per se, preferably has a construction similar to that of the upper apron expanding mechanism disclosed in aforesaid U.S. Pat. No. 3,859,909. The mechanism 122 includes a transversely-extending cross tube 130 (see also FIG. 6 wherein the front upper apron 120 is omitted for purpose of clarity), the outer ends of which are rotatably supported by left and right braces 132,134 fixed respectively to, and extending forwardly from, the corresponding left and right front upright beams 36,38 at the aforesaid similar locations therealong. Affixed to the tube 130 at locations spaced inwardly from the braces 132,134 are respective left and right pairs of generally opposite, radially-extending arms 136,138 and 140,142. At the outer ends of upper left and right arms 136,140 of the pairs thereof are rotatably mounted corresponding upper left and right idler guide sprockets 144,146, while at the outer ends of lower left and right arms 138,142 are rotatably mounted corresponding lower left and right idler guide sprockets 148,150.

An upper course, generally designated 152, of the left and right chains 124,126 of front upper apron 120 extends over and about the upper sides of upper guide sprockets 144,146 and therefrom to and under and about the lower sides of lower guide sprockets 148,150.

The pairs of arms 136,138 and 140,142 are normally disposed in the position seen in FIGS. 1 and 2 by tensioning means which includes left and right tension springs 152,154, cables 156,158 and cam plates 160,162. The left and right springs 152,154, more clearly seen in FIG. 6, are arranged to extend in generally longitudinal fashion adjacently along and above corresponding left and right side tube 52,54 of the upper rectangular frame structure of mobile frame 12. The respective rear ends of the springs 152,154 are anchored to side tubes 52,54 of the upper rectangular frame structure by upright brackets 164,166 fixed to respective rear ends of side tubes 52,54. The respective front ends of the springs 152,154 are connected to the respective ends of left and right cables 156,158 and the cables respectively extend forwardly therefrom to, and about and over, the upper sides of front left and right pulleys 168,170 mounted adjacently above the outer sides of left and right side tubes 52,54 at similar locations spaced rearwardly from the forward ends thereof by upright channel brackets 172,174. From the respective front pulleys 168,170, the cables 156,158 respectively extend downwardly to their opposite ends being respectively connected by left and right pins 176,178 to the lower portions of the outer sides of corresponding left and right cam plates 160,162. The cam plates 160,162 are respectively fixed to cross tube 130 inwardly from its opposite ends and fixed to the outer sides of upper left and right arms 136,140.

The upper course 152 of the left and right chains 124,126 of front upper apron 120 extends rearwardly and upwardly from corresponding lower left and right guide sprockets 148,150 of the takeup-and-expansion mechanism 122 to, and over and about, the upper sides of corresponding left and right upper rear idler guide sprockets 180,182 and therefrom downwardly to, and under and about, the lower sides of corresponding left and right lower rear idler guide sprockets 184,186 of the front chamber opening-and-closing mechanism 72 which will be described hereinafter. From the rear guide sprockets 184,186, the upper course 152 of front upper apron 120 merges into the rear end of a lower course, generally designated 188, of the apron 120.

The upper rear sprockets 180,182 are rotatably supported at the sides of mobile frame 12 by corresponding left and right upwardly extending brackets 190,192 which are fixed to left and right upper middle brace structures 196,198 which respectively interconnect corresponding left and right middle upright rails 32,34 and front upright beams 36,38 of the mobile frame 12.

Furthermore, the upper course 152 of the left and right chains 124,126 of front upper apron 120 extends downwardly from corresponding upper guide sprockets 144,146 of the takeup-and-expansion mechanism 120 to, and under and about, the lower sides of corresponding left and right driven sprockets 200,202 and therefrom merges into the forward end of the lower course 188 of apron 120.

The driven sprockets 200,202 for driving the front upper apron 120 are respectively fixedly mounted adjacent the opposite ends of a driven transverse shaft 204 being rotatably mounted by suitable left and right bearing structures (only right structure 206 being seen in FIG. 2) fixed on the upper sides of corresponding left and right forwardly-inclined braces 210,212 which respectively interconnect between corresponding left and right front upright beams 36,38 and front braces 214,216. The braces 214,216 are fixed at their respective lower ends to the outer ends of transverse tubular beam 62 of mobile frame 12 and respectively have rearwardly-extending upper portions 218,220 which connect to the corresponding left and right front upright beams 36,38. Also, front left and right side panels 222,224 are respectively secured about their peripheries to corresponding left and right front upright beams 36,38, forwardly-inclined support beams 56,58, forwardly-inclined braces 210,212 and front braces 214,216 so as to close the side openings respectively formed by these latter interconnected structures. The side panels 222,224, the front ends of the floor 78 and upper course of the lower apron 80, and the front end of the lower course 188 of the front upper apron 120 thereby define the inlet opening of the front chamber 68 through which crop material is delivered rearwardly from the pickup 76.

The driven transverse shaft 204 also mounts a pair of spaced annular guide hubs 226,228 (FIG. 6) at space apart intermediate locations between the ends of shaft 204. The transverse bars 128 of the front upper apron 120 located at the area of merger between the upper course 152 and the forward end of the lower course 188 engage and are supported by the forward sides of the hubs 226,228.

The drive arrangement for the driven shaft 204 which causes the front upper apron 120 to move in a generally clockwise direction, as seen in FIG. 1, will be described hereinafter.

Sidewalls for the front roll forming chamber 68 and for the middle portion of the machine 10 located between the chambers 68,70 are provided by left and right side sheets 230,232 of the mobile frame 12 which extend between and are respectively secured about their front, rear and lower peripheries to corresponding left and right longitudinal rails 14,16, lower portions of middle upright rails 32,34 and lower portions of front upright beams 36,38. Respective portions of the side sheets 230,232 adjacent the lower course 188 of the front upper apron 120 have a similar large semi-circular configuration and reach to a height somewhat greater than the diameter of the partial roll, or core, of crop material which is to be formed in the front chamber 68.

At similar locations in respective central areas of the semi-circular portions of the side sheets 230,232 of the mobile frame 12 are defined appropriately-shaped openings 234,236 with which are operably associated left and right auxiliary guide members 238,240. The auxiliary guide members 238,240, per se, preferably have a construction similar to that of the auxiliary guide members disclosed in aforesaid U.S. Pat. No. 3,859,909. The member 238,240 are pivotally mounted at their lower ends to respective side sheets 230,232 adjacent the lower ends of respective openings 234,236 and both have rounded, arcuate upper surfaces 242,244 which are respectively alideably engaged by chains 124,126 of the lower course 188 of front upper apron 120 during the initial stages of roll formation in front chamber 68 (see FIG. 20). Normally, the guide members 238,240 are disposed in an inner or extended position in which they extend inwardly through openings 234,236 in the side sheets 230,232 and into the front forming chamber 68. In such position of the members, their upper surfaces 242,244 are spaced inwardly from the side sheets 230,232 and in vertical alignment with the lower course 188 of chains 124,126 of front upper apron 120.

The guide members 238,240 are maintained in such inner positions by respective yieldable biasing means 246,248, each of which includes a compression spring interconnecting and extending between the member and a bracket fixed to and projecting outwardly from a respective side sheet adjacent the lower end of the member.

The auxiliary guide members 238,240 are forced from their inner or extended positions outwardly back through openings 234,236 to outer or retracted positions upon engagement of interior, facing surfaces of the members by the opposite ends of the crop material roll being formed in the front chamber 68. The members 238,240 also will be maintained in such retracted positions as long as the roll remains in the front chamber 68 of the machine 10. However, after discharge of the roll rearwardly to the rear chamber 70, the springs of the biasing means 246,248 restore the members 238,240 to their inner positions where the lower course 188 of the chains 124,126 of the front upper apron will again be able to slidably engage the members and form the upper boundary of a generally wedged-shaped space or cavity being defined by the upper course 188 in conjunction with side sheets 230,232, the upper course of lower apron 80 and the floor 72 which provides the initial configuration and volume of the front chamber 68 when roll forming operations are initiated therein.

The front upper apron 120, in addition to being driven along a generally clockwise, endless path as viewed in FIG. 1 and as will be explained hereinafter, is movable between contracted and expanded conditions. As shown in FIGS. 1 and 2, biasing of the takeup-and-expansion mechanism 122 provided by its spring 152,154 tends to move and hold the front upper apron 120 in a contracted condition wherein its lower course 188 engages the auxiliary guide members 238,240. As a roll being formed within the front chamber 68 increases in diameter, the takeup-and-expansion mechanism 122 will yieldably rotate in a counterclockwise direction and allow the front upper apron to progressively expand against the biasing, as seen in FIGS. 20 through 23, or move toward an expanded condition with the front chamber 68 progressively increasing in volume. In such manner, the increasing size of the roll is accommodated while the lower course of the front upper apron 120 is maintained in pressurized contact with a substantial circumferential portion of the crop material roll as it grows in size.

Therefore, the front roll forming chamber 68 is allowed to progressively increase in volume during the forming of a crop material roll therein. The roll forming region of chamber 68 is defined by and between approximately the front half of the crop material conveying means (i.e., of the floor 78 and upper course of the lower apron 80), the left and right side sheets 230,232 and the lower course 188 of the front upper apron 120. The front chamber 68 is, in effect, closed during performance of roll forming operations therein, except for a crop material front inlet opening thereto formed between the front end of the lower course of the front upper apron 120 and the upper course of the lower apron 80. Once a roll core of a predetermined desired size has been formed, the front roll forming chamber 68 is opened at its rear end for discharging the roll core through its rear end to the rear roll forming chamber 70.

FRONT CHAMBER OPENING-AND-CLOSING MECHANISM

The front chamber opening-and-closing mechanism 72 is operable to open and close the rear end of the front roll forming chamber 68. The mechanism 72 includes interconnected components, generally designated 250,252, which are respectively simultaneously operable for raising and lowering a rear portion of the front upper apron 120 and for lowering and raising a portion of the floor 78 located adjacent the rear end of the front chamber 68. The mechanism 72 further includes power means preferably in the form of left hydraulic cylinder 254 for simultaneously actuating the interconnected components 250,252.

Referring to FIGS. 1 and 2, the front upper apron raising and lowering component 250 includes left and right swingable arms 256, 258 which are respectively pivotally mounted at their lower ends by pivot elements 260,262 to the rear ends of corresponding left and right short beams 264,266 respectively horizontally secured at their inner sides to left and right side sheets 230,232 and at their forward ends to the rear sides of left and right front upright beams 36,38 of mobile frame 12. Since the pivot elements 260,262 are generally located co-axially with the common axis of the radii of the respective semi-circular portions of side sheets 230,232 and the arms 256,258, which extend along the outer surfaces of the semi-circular side sheet portions, have generally similar lengths slightly greater than the radii of the semi-circular side sheet portions, the respective outer ends of arms 256,258 protrude slightly beyond the respective peripheral edges of the semi-circular side sheet portions. The outer ends of the arms 256,258 are interconnected by a cross tube 268 which extends transversely across the machine 10 with its respective opposite ends extending above and outwardly past the respective peripheral edges of the semi-circular side sheet portions and being respective fixedly mounted on the outer ends of arms 256,258. Spaced inwardly from the respective outer ends of cross tube 268 and being located inwardly from the side sheets 230,232 are left and right brackets 270,272 secured to the cross tube 268 and extending rearwardly therefrom when the component 250 is in the upper position illustrated in FIG. 1. Left and right lower rear guide sprockets 184,186, briefly mentioned hereinbefore, are respectively rotatably secured to the outer ends of corresponding left and right brackets 270,272 along the respective outer sides thereof and in vertical alignment with chains 124,126 of the front upper apron 120. Also, a pair of lower spaced apart idler guide hubs 274,276 (FIG. 6) are rotatably supported by respective brackets 278,280 which also are respectively attached to and extend rearwardly from the cross tube 268 at spaced apart intermediate locations between the ends of the tube 268. The rear sides of the hubs 274,276 engage and support the transverse bars 128 of front upper apron 120 located at the area of merger between the upper course 152 and rear end of the lower course 188 of apron 120.

The floor portion lowering and raising component 252, as seen in FIGS. 1 and 2 and in greater detail in FIGS. 3 and 4, includes a series of side-by-side rectangular spaced apart ramps 282 disposed, across the floor 78, each one aligned laterally with the next one in the series thereof and positioned between adjacent floor channels 110 within which the lower apron chains 94 are disposed. The ramps 282 are respectively mounted in a corresponding series of side-by-side spaced apart rectangular openings 284 defined in the floor 78 between adjacent floor channels 110. Two of the transverse floor supporting channel beams 108 underlie the floor 78 adjacent respective forward and rear ends of the openings 284. Each of the ramps 282 is comprised by a top planar portion 286 and left and right spaced apart vertical side portions 288,290 which respectively depend downwardly from opposite longitudinally-extending edges of the top planar portion 286. Pairs of spaced apart, rearwardly-extending tabs 292 fixed to the rear side of front channel beam 108 and the forward ends of ramp side portions 288,290 have aligned holes formed therein through which a transverse rod 294 extends which pivotally mounts the ramps 282 at their forward ends to the tabs 292. The transverse rod 294 at its respective opposite ends extends through and is secured to side sheets 230,232. Also, each of the ramps 282 at its rear end includes a rearwardly and downwardly extending tail 296, the lower tip of which remains extending through the rear end of the respective opening 284 when the ramp 282 is in its raised position as seen in FIG. 4 in order to prevent crop material residue from inadvertently entering into the opening 284 and becoming lodged under the ramp 282 which would impede lowering of the ramp 282. The component 252 also includes a transverse rockshaft 298 which extends between the sides of mobile frame 12 and underlies the rear ends of floor ramps 282. The rockshaft 298 at its respective outer ends extends through and is mounted by left and right bearings 300,302 to corresponding left and right side sheets 230,232. A series of side-by-side spaced apart lifting fingers 304 are connected at their inner ends to the rockshaft 298 and are vertically aligned with respective contacts pads 306 fixed to the undersides of respective ones of the floor ramps 282 near the rearward ends thereof. The fingers 304 normally extend radially forwardly from the rockshaft 298 and respectively have downwardly-extending arcuate-shaped outer ends 308 which engage and lift the corresponding pads 306 to cause counterclockwise pivoting of the ramps 282 upwardly when the rockshaft 298 is rotated in a clockwise direction, as viewed in FIG. 4.

Left and right means, generally designated 310,312, are illustrated in FIGS. 1 and 2 which interconnect the components 250,252 such that arms 256,258 are lowered simultaneously when floor ramps 282 are raised for closing the rear end of front chamber 68 as seen in FIGS. 20 through 23 and such that arms 256,258 are raised simultaneously when ramps 282 are lowered for opening the rear end of front chamber 68 as also seen in FIGS. 17 through 19 and 24. The left means 310 includes an arcuate member 314 fixed to the left outer end of the rockshaft 298 so as to be rotatable therewith. The rear upper end of member 314 of pivotally connected to the lower rear end of a left turnbuckle device 316 which, in turn, is pivotally connected at its upper forward end to the rear side of the left arm 256. The right means 312 includes a short arm 318 fixed at its lower front end to the right outer end of the rockshaft 298 so as to be rotatable therewith. The upper rear end of short arm 318 is pivotally connected to the lower rear end of a right turnbuckle device 320 which, in turn, is pivotally connected at its upper forward end to the rear side of the right arm 258.

For simultaneously moving the interconnected components 250,252, left hydraulic cylinder 254 is pivotally connected at its piston rod end to the front upper end of arcuate member 314 and is pivotally anchored at its cylinder end to the rear end of a brace 322 which is fixed to and extends along the outer surfaces of right upright beam 38 and right side panel 224. Extension of cylinder 254 causes arcuate member 314, and thereby rockshaft 298 and short arm 318, to rotate in a clockwise direction as viewed in FIG. 1, which results in fingers 304 engaging and lifting pads 306 and thereby pivoting ramps 282 upwardly and at the same time, through left and right turnbuckle devices 316,320, pulling pivotal arms 256,258 downwardly until the rear ends of ramps 282 are disposed closely adjacent the rear end of the lower course 188 of the front upper apron 120 which, in effect, closes the rear end of front chambers 68. Retraction of cylinder 254 causes the arcuate member 314, rockshaft 298 and short arm 318 to rotate in a counterclockwise direction, as viewed in FIG. 1, back to their respective positions as seen in FIGS. 1 and 2 which results in the ramps 282 lowering back to their horizontal positions within the plane of the floor 78 due to gravity and the arms 256,258 being pivoted upwardly to their positions of FIGS. 1 and 2, which remotely spaces the rear end of the lower course 188 of the front upper apron 120 from the rear ends of the ramps 282 and, in effect, opens the rear end of the front chamber 68. By adjusting the turnbuckle devices 316,320, the displacements of arms 256,258 and thus the rear end of the front upper apron 120 at both the raised and lowered positions thereof relative to the floor 282 may be adjusted.

Means for actuating the cylinder 254 will be described later on in connection with the detailed description of the hydraulic and mechanical control components which synchronize the operations performed with the machine 10.

REAR ROLL FORMING CHAMBER

Referring again to FIGS. 1 and 2, the rear chamber 70 includes an upper frame, generally designated 324, pivotally connected to and supported on the rear portion of the mobile frame 12, a rear upper apron, generally designated 326, and means for movable mounting the floor 78 and upper apron 122 to both the mobile frame 12 and the rear upper frame 120 at a location above generally the rear half of the floor 78 and lower apron 80 which form the bottom of the rear chamber 70. The mounting means includes a front take-up-and-expansion mechanism, generally designated 328, for movably mounting the forward portion of the rear upper apron 326 to the mobile frame 12, a rear takeup-and-expansion mechanism, generally designated 330, for movably mounting a middle upper portion of the rear upper apron 326 to the upper frame 324 and additional components for movably mounting lower front, middle and rear portions of the rear upper apron 326 to the mobile frame 12. The takeup-and-expansion mechanisms 328,330 control contraction (takeup) and expansion of the rear upper apron 326 during roll formation in the rear chamber 70.

The upper frame 324, per se, preferably has a construction similar to that of the upper frame disclosed in aforesaid U.S. Pat. No. 3,859,909, consisting of left and right side portions 332,334 respectively composed of left and right straight members 336,338, the opposite ends of which are respectively connected to the opposite ends of corresponding arcuate members 340,342. Left and right side panels 344,346 are respectively secured about their peripheries to corresponding left and right straight members 336,338 and arcuate members 340,342 so as to close the side openings respectively formed by these members. The side portions 332,334 of the upper frame 324 are also transversely interconnected by two spaced apart cross channels 348,350 which connect at their respective opposite ends with the arcuate members 340,342. Further, left and right reinforcing beams 352,354 are attached to respective side panels 344,346 and interconnect respective straight members 336,338 and arcuate members 340,342 at approximate middle locations therealong.

The uppermost end of the respective side portions 332,334 of upper frame 324 are pivotally connected by respective pivot elements 356,358 to suitable bearing bracket structures 360,362 mounted to respective upper ends of left and right forwardly-inclined side beams 40,42 of the mobile frame 12. The upper frame 324 is thereby mounted to the mobile frame 12 for pivotal movement between a lower, closed position, as seen in FIGS. 1, 2 and 7 wherein left and right straight members 336,338 of upper frame 324 rest upon corresponding left and right side beams 40,42 of mobile frame 12, and an upper, open position, as seen in FIGS. 7 and 21. The upper frame 324 comprises part of the rear chamber opening and closing mechanism 74 which will be described later on.

Except for its greater length in the machine 10, the rear upper apron 326, per se, like front upper apron 120, preferably has a construction similar to that of the upper apron disclosed in U.S. Pat. No. 3,915,084. The apron 326 is composed of a pair of left and right endless, flexible link-type chains 364,366, illustrated in FIGS. 1 and 2, located adjacent corresponding interior sides of the mobile and upper frames 12, 324, with a series of rigid bars 367 extending transversely between and connected at their opposite ends to the chains 364,366 at longitudinally spaced intervals therealong. The bars 367 thereby extend across substantially the full width of the rear chamber 70. In cross section, the bars 367 are preferably cylindrical, but may be square or any other suitable geometric shape, for purposes of offering resistance to bending of the bars, especially when engaging the periphery of a roll of crop material being formed within the rear chamber 70, such as illustrated in FIGS. 18 through 20.

The rear upper apron 326 is movably supported on the mobile and upper frames 12, 324 by the above-mentioned takeup-and-expansion mechanisms 328,330 and other additional mounting components briefly referred to above.

Positioned adjacent the respective side portions 332,334 of upper frame 324 are left and right arcuate guide bars (not shown) which are secured to and spaced inwardly from corresponding left and right arcuate members 340,342 by suitable brackets (not shown), such bars and brackets being substantially of the same construction as that disclosed in aforesaid U.S. Pat. No. 3,859,909. The arcuate guide bars conform generally to the profile of the arcuate members 340,342 of upper frame 324 and the upper course, generally designated 368, of the chains 364,366 of the upper apron 326 slideably engage and move along the respective outer edges of the arcuate guide bars as the apron 326 is moved in an overall clockwise direction, as seen in FIG. 1.

At the lower ends of the left and right side portions 332,334 of upper frame 324 are respectively mounted left and right lower idler guide sprockets 370,372 being respectively rotatably supported by bracket plates 374,376 which are respectively attached to and depend forwardly and downwardly from a cross tube (not shown) extending transversely between and connected at its opposite ends to the lower ends of corresponding left and right straight members 336,338 of upper frame 324. A pair of lower spaced apart idler guide hubs (not shown) are rotatably supported by respective clevises (not shown) which also are respectively attached to and depend forwardly and downwardly from the cross tube at spaced apart intermediate locations between the ends of the tube. The upper course 368 of the chains 364,366 of the rear upper apron 326 extends about the lower sides of the lower guide sprockets 370,372 and therefrom merges into the rear end of the lower course of the apron 326, such being indicated generally by 380, while the tranverse bars 367 located at the area of merger between the courses 368,380 engage the lower sides of the hubs.

Adjacent the upper ends of the left and right side portions 332,334 of the upper frame 324 are mounted the corresponding left and right portions of the rear takeup-and-expansion mechanism 330 as well as left and right upper idler guide sprockets 382,384, the latter being respectively rotatably supported on the interior sides of left and right bracket channels 386,388 which are respectively connected to the upper ends of corresponding left and right arcuate members 340,342 of upper frame 324 and extend upwardly thereform.

The rear takeup-and-expansion mechanism 330 includes a transversely-arranged tubular shaft (not shown), the outer ends of which extend respectively through and are rotatably supported by left and right bracket plates 392,394 positioned rearwardly of corresponding left and right bracket channels 386,388 and connected thereto as well as to the upper ends of corresponding left and right arcuate members 340,342 of upper frame 324. The rear takeup-and-expansion mechanism 330 further includes left and right arms 396,398 respectively attached to corresponding left and right outer ends of transverse tubular shaft and extending in similar fashion radially therefrom normally in an upwardly and rearwardly inclined position. Left and right outer idler guide sprockets 400,402 are rotatably mounted to the respective upper inwardly-projecting ends of corresponding left and right arms 396,398. The rear takeup-and-expansion mechanism 330 still further includes means for biasing the arms 396,398 to their normal inclined position, as seen in FIGS. 1 and 2, which includes left and right elongated tension springs 404,406 respectively located outwardly along side portions 332,334 of the upper frame 324 and left and right triangular-shaped channels 408,410 respective secured to and depending from corresponding left and right arms 396,398. The left and right tension springs 404,406 are pivotally anchored at their rearward ends to respective left and right angle brackets 412,414 fixed to, and extending outwardly from, corresponding left and right arcuate members 340,342 of upper frame 324. The forward ends of the left and right springs 404,406 are pivotally attached to the respective lower ends of corresponding left and right triangular-shaped channels 408,410.

The upper course 368 of the chains 364,366 of the rear upper apron 326 further extends about the upper sides of the upper idler guide sprockets 382,384 as well as the outer idler guide sprockets 400,402 of the rear takeup-and-expansion mechanism 330.

At similar locations adjacent to, and spaced downwardly from the upper ends of the left and right middle upright rails 32,34 of mobile frame 12 is mounted the left and right portions of the front takeup-and-expansion mechanism 328 of the rear chamber 70. The latter mechanism, per se, like the takeup-and-expansion mechanism 122 of the front chamber 68, preferably has a construction similar to that of the upper apron expanding mechanism disclosed in aforesaid U.S. Pat. No. 3,859,909. The front takeup-and-expansion mechanism 328 of the rear chamber 70 includes a transversely-extending cross shaft 416 (see also FIG. 6 wherein the rear upper apron 326 has also been omitted for the sake of clarity), the outer ends of which are rotatably supported by left and right channel brackets 418,420 fixed respectively to, and extending forwardly from, the corresponding left and right middle upright rails 32,34 of mobile frame 12 at the aforesaid similar locations therealong. Affixed to the shaft 328 at locations spaced inwardly from the brackets 418,420 are respective left and right pairs of generally opposite, radially-extending arms 422,424 and 426,428. At the outer ends of forward left and right arms 422,428 of the pairs thereof are rotatably mounted corresponding front left and right idler guide sprockets 430,432, while at the outer ends of rearward left and right arms 424,428 are rotatably mounted corresponding rear left and right idler guide sprockets 434,436.

The upper course 368 of the left and right chains 364,366 of the rear upper apron 326 extends generally downwardly from the previously described corresponding left and right upper idler guide sprockets 382,384 to under and about the lower sides of the corresponding left and right rear guide sprockets 434,436 of mechanism 328 and therefrom upwardly to, and over and about, the upper sides of the corresponding left and right front guide sprockets 430,432 of mechanism 328.

The pairs of arms 422,424 and 426,428 are normally disposed in the position seen in FIGS. 1 and 2 by tensioning means which includes left and right tension springs 438,440, cables 442,444 and cam plates 446,448. The left and right springs 438,440, more clearly depicted in FIG. 6, are arranged to extend in generally longitudinal fashion adjacently along the respective inner sides of corresponding left and right side tubes 52,54 of the upper rectangular frame structure of mobile frame 12. The respective forward ends of the springs 438,440 are anchored to the front cross tube 48 of the upper rectangular frame structure by upright brackets 450,452 fixed to the cross tube 48 adjacent and inwardly of its opposite ends. The respective rearward ends of the springs 438,440 are connected to the respective ends of left and right cables 442,444 and the cables respecitively extend rearwardly therefrom and about the rear sides of left and right pairs of inner and outer pulleys 454,456 and 458,460 mounted below corresponding left and right corner plates 462,464 which bridge the intersection of side tubes 52,54 and middle cross tube 48 of the upper rectangular frame structure. From the respective outer pulleys 456,460 of the left and right pairs of pulleys, the cables 442,444 respectively extend forwardly and about the upper sides of left and right pulleys 466,468 rotatably mounted adjacent and below the rear ends of corresponding left and right side tubes 52,54 of the upper rectangular frame structure. From pulleys 466,468, finally the cables 442,444 respectively extend downwardly to their opposite ends being respectively connected by left and right pins 470,472 to the lower portions of the outer sides of corresponding left and right cam plates 446,448. The cam plates 446,448 are respectively fixed to cross shaft 416 inwardly from its opposite ends and fixed to the outer sides of forward left and right arms 422,426.

Furthermore, the upper course 368 of the left and right chains 364,366 of the rear upper apron 326 extends downwardly from corresponding left and right front guide sprockets 430,432 of the front takeup-and-expansion mechanism 328 to, and over and about, the lower sides of corresponding left and right driven sprockets 474,476 and therefrom merges into the front end of the lower course 380 of the rear upper apron 326.

The driven sprockets 474,476 for driving the rear upper apron 326 are respectively fixedly mounted adjacent the opposite ends of a driven cross shaft 478 being rotatably mounted to left and right mounting structures 480,482 affixed to and projecting upwardly from the respective forward ends of corresponding left and right pivotal arms 484,486. The arms 484,486 normally extend from their forward ends in a rearwardly-inclined direction to rear ends being pivotally mounted respectively at 488,490 to corresponding left and right forwardly-inclined side beams 40,42 of the mobile frame.

Means to be described later on in conjunction with the description of the rear chamber opening-and-closing mechanism 74 normally maintains the arms 484,486 in their rearward-inclined direction which disposes the driven sprockts 474,476 and shaft 478 in the lowered position, as seen in FIGS. 1 and 2.

The driven shaft 478 also mounts a pair of spaced apart annular guide hubs 492,494 (FIG. 6) at spaced apart intermediate locations between the ends of the shaft 478. The transverse bars 367 of the rear upper apron 326 located at the area of merger between the upper course 368 and the forward end of the lower course 380 engage the forward sides of the hubs 492,494.

The drive arrangement on the machine 10 for the driven shaft 478 which causes the rear upper apron 326 to move in a generally clockwise sense, as seen in FIG. 1, will be described later on.

At similar locations in respective lower, central areas of the left and right sheets 44,46 of the mobile frame 12 are defined appropriately-shaped openings 496,498 with which are operably associated left and right auxiliary guide members 500,502. Like members 238,240 of the front chamber 68, the auxiliary guide members 500,502, per se, preferably have a construction similar to that of the auxiliary guide members disclosed in aforesaid U.S. Pat. No. 3,859,909. The members 500,502 are pivotally mounted at their lower ends to respective side sheets 44,46 adjacent the lower ends of respective openings 496,498 and both have rounded, arcuate upper surfaces 504,506 which are respectively slideably engaged by chains 364,366 of the lower course 380 of upper rear apron 326 during the initial stages of roll formation in rear chamber 70. Normally, the guide members 500,502 are di